In many areas of commerce, containers and, in particular, stackable containers are used to hold and/or transport products. For the area of produce (e.g., fresh fruits and vegetables), such stackable containers are particularly important. Conventional packaging containers are typically formed from blanks made of corrugated board. Such corrugated board generally contains two outer layers of paperboard or cardboard (which generally has a relatively heavy weight), with an inner layer of corrugation (e.g., corrugated paper), but it may contain further layers (e.g., of an external paper or plastic sheet for further support, waterproofing and/or marking, e.g., with advertising and/or identification information; a further inner layer or sheet [e.g., of paper or plastic] between two layers of corrugation; etc.) or contain different materials (e.g., plastic sheet having a relatively high stiffness or modulus of elasticity).
Such packaging containers are generally formed from container blanks Container blanks are pre-cut (e.g., to cut out the outline of the blank, cut holes within the bank [e.g., for ventilation, indexing, grip locations, and/or other purposes], and/or to cut separations lines between flaps or other features of the container). The blanks are generally pre-scored to facilitate folding the blank along desired fold-lines. In addition, container blanks may be printed on one or both sides for identification and/or marketing purposes.
Container blanks may be folded manually to form erected containers. However, to improve efficiency and uniformity and to reduce labor costs it is often preferable to form the containers automatically in a machine configured for the purpose. Existing container forming machines suffer from some drawbacks. For example, the act of folding the cardboard along a fold-line may cause a deformity or bulging in the container material near the fold line if the surfaces of the blank are not adequately supported, especially if the blank has cut-out areas (e.g., ventilation holes) close to the fold-line. Containers deformed in this manner may not be commercially acceptable, so that the efficiency and/or useful throughput of the forming apparatus is reduced.
Therefore it is desirable to provide an apparatus and method for automatically forming containers with good uniformity of result.